Currently, saltwater baitfishes are the preferred live bait of saltwater anglers. The majority of saltwater anglers gather live bait or use artificial bait sources, causing the numbers of natural saltwater baitfish to be lower than ever. In recent years, the Gulf of Mexico states have reported that during winter months the supply of live bait is not sufficient to meet the demand of saltwater anglers. On May 15, 2003, the journal Nature reported that oceanic fish species worldwide have been so systematically over-harvested that fewer than ten percent of 1950 levels remained. Further, collecting live saltwater bait is often subject to local bag limits because the harvest and use of a native species as bait increases pressure on the saltwater ecosystem as a whole.
Several additional factors that discourage anglers from using live bait include the following: the lack of immediate availability, the increased time associated with collecting live bait from the wild, and the sensitivity of natural baitfish to artificial living environments needed to store the baitfish until used. The inventor views the limited availability of saltwater baitfish as a severe problem, both for the native saltwater fish population as well as the sport-fishing industry.
A clear need exists for short-lived salt-tolerant freshwater baitfish that are tolerant to limited exposure to saltwater conditions associated with saltwater angling. Such baitfish must operate as living, moving, highly desirable bait for a limited time, yet must have only limited saltwater tolerance such that extended exposure will eventually kill the fish. Aquaculture production of short-lived salt-tolerant freshwater baitfish will provide alternative sources of stocks, will decrease demand on natural populations of native fishes, and will help satisfy the growing demand of saltwater angling. Moreover, the use of short-lived salt-tolerant freshwater baitfish will accomplish these tasks without jeopardizing the health of native fishes, without decreasing natural food supplies, and without introducing normative fish to saltwater ecosystems. As such, the present invention links the spheres of artificial bait and the use of native saltwater species as baitfish.
Three major species are cultured for freshwater bait—the golden shiner, Notemigonus crysoleucas; the goldfish, Carassius auratus; and the fathead minnow, Pimephales promelas. These three species are easily spawned and are popular as freshwater aquaculture fishes because they are easy to raise and harvest. As a result, these fishes have been used in freshwater aquaculture systems for many years. However, these fishes have a terribly short lifespan when exposed to saltwater conditions, lasting less than a few minutes.
A simple method for producing short-lived salt-tolerant freshwater baitfish not based upon an artificial modification of the genome of the fish is highly desirable. The present invention contemplates the use of highly selective breeding techniques and the use of specialized breeding stations to identify normative genetic pressure changes and to select only those short-lived salt-tolerant freshwater baitfish that are capable of sustaining life in saltwater conditions for a duration sufficient to meet the needs of the saltwater sport fishing industry.